Bentonite sulfur



Patented Dec. 29, 1953 UETED BENTONITE SULFUR Vincent J. Russo and John port, N. Y., assignors to Chemical Corporation, S

poration of Delaware No Drawing. Application F. Les Veaux, Middle- Food Machinery and an Jose, Calif., a corllIay 16, 1950,

Serial No. 162,390

2 Claims. (01. 167

The present invention relates to an improved colloidal fungici dal sulphur composition and more particularly to a composition of fused sulphur and bentonite clay.

It has been known for a number of years that the so-called bentonite sulphur fusion product is an excellent fungicidal composition particularly suitable for of fungi such as fungi.

Bentonite sulphur as use in inhibiting the growth smuts, rusts and mildews and,

prepared heretofore was made by fusing elemental sulphur with bentonite clay generally at point of sulphur resultant fused p and was used as temperatures above the melting and below about 140 C. The roduct was subsequently ground a fungicide either as a dust or as a spray merely by suspending the bentonite sulphur in water.

.fungicide on ma stance, on apple on stone fruits for smut as, for

The product was an excellent ny types of fungus as, for inscab, on brown rot occurring such as peaches and the like, instance, the mildew occurring European types, as a control instance, wet smut and various types of spots such as cherry leaf spot.

It is believed that the effectiveness of bentonite sulphur is directly traceable to the content of colloidal sulphur present in the fused end product and, although the usual form of bentonite sulphur appearing on the market contains from about to about 33% sulphur or more, the

amount of colloidal sulphur present in the usual commercial type of bentonite sulphur is only a small fraction of this amount It is an object pare a fungicida of the present invention to pre- 1 composition of bentonite and sulphur of greater fungicidal effectiveness than has been prepared heretofore.

It is the corollary object of the invention, therefore, to prepare a bentonite sulphur composition containing a greate proportion of colloidal sulphur than was possible heretofore.

It is also an object of the invention, therefore, to render more effective as a fungicide the sulphur included in the bentonite.

The various advantages of the invention are obtained by hydrating the bentonite sulphur mixture during o after the bentonite and sulphur have been fused.

tonite is hydrated or leafs which bentonite are in It is believed that when benthe individual adjacent plates constitute the structure of eifect pressed apart one from the other at a distance which is greater than th average ato mic diameter of the sulphur tially uniform color. and ground.

whereby sulphur in extremely divided form and substantially of molecular diameter may enter and be retained between the individual adjacent leafs or plates of the bentonite itself. The sulphur in this finely divided form is then available and may be discharged from the bentonite in an active fungicidal form.

A sample of bentonite sulphur was prepared by the procedure outlined in U. SePatent 1,550,650 of August 18, 1925, by fusing one part of sulphur by Weight with two parts of bentonite. The fusion was effected at. 140 C. and this temperature maintained untilthe mass was of substan- The .product was cooled As this product was made in accordance with the procedure normally employed in the manu facture' of commercial samples appearing upon the market it is designated herein as commercial bentonite sulphur fungicide. Th content of colloidal sulphur in this sample was determined in accordance with the standard procedure recommended in the Niagara Analytical Abstracts published by Niagara Chemical Division, Food Machinery and Chemical Corporation, Middleport, New York, 5th edition, page 45; that is, a 1 gram sample is ground and thoroughly mixed with water in a 500 cc. graduate and the contents permitted to settle for 16 hours whereupon 400 cc. of the milky suspension is siphoned off. oxidized with sodium peroxide and the sulphur determined by precipitation as the sulphate.

The amount of colloidal sulphur based on the weight of bentonite sulphur was found to be 7.72%.

In accordance with the procedures of the present invention two parts by weight of 10 mesh bentonite and one part by weight of powdered sulphur were mixed and then heated at 140 C. for one hour, Th product was cooled and then permitted to stand with frequent agitation in an atmosphere of 96% humidity for 124 hours at a temperature below C. The moisture in the resultant product had increased to 14%. This product was again heated at C. for one hour and again placed in a humid atmosphere. A determination of the colloidal sulphur showed the presence of 15.7% colloidal sul hur. A third fusion of this product, after humidification, produced a bentonite sulphur composition containing 20.4% colloidal sulphur; that is, of the total sulphur present in th product 20.4 over 33 represented the proportion of colloidal sulphur as 60%. Three and four fusions with intermittent humidification have produced products containing 26 to 27% .dusted with aspore ffor bean rust j(Uromyces appendiculutus). "The .treated plants .and the controls 'were placed'in .lesions on the controls, and .on;.thetreatedy plants were counted and the "the 'treated ;plants "sub- 1 tractedjfrom theJnumber of lesions on the conin the "table below:

treated with aspray. containing. 0.125

colloidal sulphur; that is, a transformation of 88% of the total sulphur present into the colloidal condition in contrast with a transformation under the best conditions heretofore of not more than 30 to 35% of the total sulphur into the colloidal or active condition. The humidification towhich thetmixture is subjected between fusions, should be carried to a point where the fusion mixture possesses at least 3% moisture.

To test the effective fungicidal action of the product of the present invention various samples of bentonite sulphur jwere*diluted imwater to a concentration as specified 'ibelow, either 0.125% or a concentration twice this amount, and the fungicidal suspension then sprayed under standard testing conditions upon potted Pinto beans. After the spray had dried, and -in accordance with conventional test procedures. plants so treated with the fungicide were then dust in standard fashion a temperature controlled humidity chamber for a period of .24 hours and thenweremaintained e under .standard'conditions side by-side in the same greenhouse'for a period-"of days. The that is untreated plants,

number of lesions on trol or untreated 'plantsidivided by the number of; lesions on the control; plants was reported as percent control. The results ,of'this" test-appear k Percent IType of bentonite. sulfur I @1101- Gommercial bentonlte-sulfur Instant invention-i3 fusions 4tonite sulphur composition is directly'traceable .Thus plants of the .dry fungicidal composition containing 7.72% colloidal sulphur showed',.52 as many lesions as untreated plants. At vthesaine dilution a'sampleof-bentonite sulphur containing 14% colloidal. sulphur showedas many lesions .as untreated plants. Against the samedilution the sample.with-20A% colloidal sulphur showed only 12% as many lesions as theuntreatedplants. It will be noted that .a dilution of spray. of 0.251% of the sample ,containingzoxi. .colloiclalsulphur gave. substantially 100%-control.

to the amount of colloidal sulphur.

tested accordingito" the analytical procedure de- .-.scribed,.above, will-exhibit more than 14% colloi- .dalsulphuror. more than of the total sulphur content as colloidal.

*Bythe humidification process of the present invention the proportion of sulphur determined as colloidal sulphur was increased by repeated fusions and intermediate moisture take-up so that aafterfour. fusions- 88 .of .the. sulphunhadheen changed to .the colloidal state (29% colloidal sulphur .ina'2 .loentonite 1 sulphur hatch).

The usual commercial, product. willhe. prepared .to. containla total sulphur content of..3035%.but -maycontaintotal sulphur. .inthe range25 to the. remaindeninert. materialand such. .aproduct designated. hereinas bentonite sulphur.

.What .is .claimed .is: V

.1. The method of .malcing an .improved ben tonite sulphur which comprises heating bentonite and sulphur at.:a temperature .abOve-themelting point of sulphurand below about-160 C., placing the fusion. mixture in a humid atmosphere atra temperature below C. .until the -.product possesses at. least:3 moisturecand repeatingtthe procedure ,until: morathan-AB of :the total sulphur. has been changed. to the colloidalcondition.

2. .The .method of making an improved .ben- .tonite sulphur wh-ich comprises heating .bentonite and sulphur.at-atemperature above the melting point. of sulphur and .below .-about.. C., placing the fusion. mixture in ahu-I-nid-atmosphereat .-a temperature below 100C. until the product possesses-atleast 3% ..-moisture -andirepeating the procedure until. 55% to 88% of the. total-sulphur has been changed to the colloidal condition.

Number Name Date 1,550,650 Banks .Aug. 18,1925 1,662,550 .Vree1and,n Mar. 13, 1928 1,934,984 ,-McDanie1. Nov. 1.4, 1933 'QTHER'iREFERENCES De .Ong, JournalIEconomic Entomology, volume 17, pages 1533 ,to.;53.8, .iQctober .1924. (CODY .inJDivision A31) 

4. THE METHOD OF MAKING AN IMPROVED BENTONITE SULPHUR WHICH COMPRISES HEATING BENTONITE AND SULPHUR AT A TEMPERATURE ABOVE THE MELTING POINT OF SULPHUR AND BELOW ABOUT 160* C., PLACING THE FUSION MIXTURE IN A HUMID ATMOSPHERE AT A TEMPERATURE BELOW 100* C. UNTIL THE PRODUCT POSSESSES AT LEAST 3% MOISTURE AND REPEATING THE PROCEDURE UNTIL MORE THAN 45% OF THE TOTAL SULPHUR HAS BEEN CHANGED TO THE COLLOIDAL CONDITION. 